Sort each dataframe in a dictionary of dataframes

Question

Thanks to @Woody Pride's answer here: https://stackoverflow.com/a/19791302/5608428, I've got to 95% of what I want to achieve.

Which is, by the way, create a dict of sub dataframes from a large df.

All I need to do is sort each dataframe in the dictionary. It's such a small thing but I can't find an answer on here or Google.

import pandas as pd
import numpy as np
import itertools

def points(row):
    if row['Ob1'] > row['Ob2']:
        val = 2
    else:
        val = 1
    return val

#create some data with Names column
data = pd.DataFrame({'Names': ['Joe', 'John', 'Jasper', 'Jez'] *4, \
                     'Ob1' : np.random.rand(16), 'Ob2' : np.random.rand(16)})

#create list of unique pairs
comboNames = list(itertools.combinations(data.Names.unique(), 2))

#create a data frame dictionary to store your data frames
DataFrameDict = {elem : pd.DataFrame for elem in comboNames}

for key in DataFrameDict.keys():
    DataFrameDict[key] = data[:][data.Names.isin(key)]

#Add test calculated column
for tbl in DataFrameDict:
    DataFrameDict[tbl]['Test'] = DataFrameDict[tbl].apply(points, axis=1)

#############################
#Checking test and sorts
##############################

#access df's to print head
for tbl in DataFrameDict:
    print(DataFrameDict[tbl].head())
    print()

#access df's to print summary  
for tbl in DataFrameDict:    
    print(str(tbl[0])+" vs "+str(tbl[1])+": "+str(DataFrameDict[tbl]['Ob2'].sum()))

print()

#trying to sort each df   
for tbl in DataFrameDict:
    #Doesn't work
    DataFrameDict[tbl].sort_values(['Ob1'])
    #mistakenly deleted other attempts (facepalm)

for tbl in DataFrameDict:
    print(DataFrameDict[tbl].head())
    print()

The code runs but won't sort each df no matter what I try. I can access each df no problem for printing etc but no .sort_values()

As an aside, creating the df's with tuples for names(keys) was/is kind of hacky. Is there a better way to do this?

Many thanks

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.sort_values.html — Pedro Lobito, Apr 05 '19 at 19:23

score 1 · Accepted Answer · answered Apr 05 '19 at 20:20

1

Looks like you just need to assign the sorted DataFrame back into the dict:

for tbl in DataFrameDict:
    DataFrameDict[tbl] = DataFrameDict[tbl].sort_values(['Ob1'])

answered Apr 05 '19 at 20:20

Chris Adams

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1

Is it possible to laugh at yourself and kick yourself at the same time? ;) Thanks! guess I just needed fresh eyes on it. – DublinMeUp Apr 06 '19 at 01:08

Sort each dataframe in a dictionary of dataframes

1 Answers1